3-Hydroxy-1,3-oxazinan-4-one und 1,4,2-Dioxazole aus 3-Hydroxycarbohydroxamsäuren und Carbonylverbindungen

3-Hydroxy-1,3-oxazinan-4-ones and 1,4,2-Dioxazoles from 3-Hydroxycarbohydroxamic Acids and Carbonyl Compounds The acid-catalysed cyclization of 3-hydroxycarbohydroxamic acids 4 with benzaldehyde dimethylacetal or paraformaldehyde gives 3-hydroxy-1,3-oxazinan-4-ones 5 and 7 . Depending on the substituents, the reaction of 4 with cyclohexanone produces either 1,3-oxazinan-4-ones of type of 8 or 1,4,2-dioxazole of type 9 .